1. Field of the Invention
The present invention relates to the field of carrying cases.
2. Prior Art
Carrying cases are well known in the prior art. The present invention, however, is particularly suited for use in cases for soft drinks and the like, and is therefore described in detail herein with respect to a case for such purposes. Because the prior art and the problems related thereto with respect to soft drink cases is representative generally of the prior art and problems associated with cases for other purposes, the prior art described herein shall be limited to beverage cases, it being understood, however, that the present invention is not necessarily so limited.
Beverages have been commonly packaged in some form of carrier containing six individual beverage containers commonly referred to as a six-pack, though of course carriers of other quantities such as carriers containing eight containers of beverage are also commonly used. These carriers, whether of cardboard, plastic or other materials, are convenient for the consumer but are too small for efficient handling by bottlers and other persons in the distribution chain. Accordingly it is common practice to use cases for carrying a plurality of such carriers so as to provide more efficient handling of the product. Such cases, until recently, were generally fabricated from wood, with the associated equipment of the bottlers and those in the distribution chain, such as uncasers, casers, truck racks, etc. being sized to readily accept such cases.
In very recent years molded plastic cases have been used as substitutes for wooden cases, such plastic cases having the advantage of greater cost effectiveness. Given the considerations of cost, impact resistance and general appearance and durability, high density polyethylene is generally considered the preferred material for use in molding such cases. However polyethylene also exhibits very substantial self lubricating qualities, thereby giving rise to certain disadvantages to which the present invention is directed. In particular when cases of bottles are stacked, each case rests on the top of the bottles thereunder, with the self-lubricating characteristics of the polyethylene detracting from the general stability of the overall stack. Also the effective "slipperiness" of a polyethylene case when resting on a flat surface is generally undesirable, and in some cases may prohibit the use of such cases as a substitute for wooden cases. In particular cases are commonly handled at a bottling plant on conventional conveyor systems which may include transfer conveyors, etc., the successful operation of which depend upon adequate friction between the conveyor surface and the cases being conveyed thereby. Further, in many instances such conveyor systems include inclines, negotiation of which may require at least a minimum coefficient of friction between the case and the conveyor. Accordingly successful application of molded plastic cases in such instances requires the providing of suitable friction between the conveyor and the cases.
Accordingly in the prior art, efforts have been made to provide separate high friction members on the bottom of cases, such as rubber or high friction plastic feet so that the coefficient of friction of these feet rather than that of the polyethylene determines the driving force created by the conveyor. Typically in the prior art such feet were generally in the form of circular members inserted through through-holes in the bottom of the case, the feet having an enlarged head on both sides of the through-hole so as to be retained thereby. While the friction desired may be obtained in this manner, such an arrangement has certain specific disadvantages to which the present invention is directed. Since the feet are relatively local and are confined in position only by engagement with the edges of the holes, their durability is perhaps less than desired. Further, in the case of beverages, the existence of the through-hole in the bottom of the case with the elastic foot therein tends to entrap beverage syrup in the small gaps defined thereby, making cleaning of the inside of the case difficult, and promoting the growth of obviously undesired microorganisms.
The cases known prior to this invention did not provide for carrying stackable bottle carriers, particularly molded plastic carriers as disclosed, by way of example, by Torokvei in U.S. Pat. No. 4,040,517, issued Aug. 9, 1977, entitled "STACKING CASE". The prior art cases accommodate these new bottle carriers for stacking during shipping or storage in a conventional manner. In particular, the carrier handle extends above the sides of the prior art cases, with the prior art cases preventing nesting of the carriers and cases.